Pointers or values: when to use * and & in Go parameters and return values?

Hello everyone! I recently started learning Go, and I keep struggling with the question: when should I pass parameters to a function by pointer, and when by value? Same question for return values. I kind of understand that pointers allow avoiding data copying, but doesn't Go copy everything anyway? Or not? I wrote a small example where I create a User struct and try to modify it: ```go type User struct { Name string Age int } func updateUser(u User) { u.Name = "New Name" // doesn't work as expected } func updateUserPtr(u *User) { u.Name = "New Name" // works } ``` But here's what confuses me: I thought everything in Go is passed by value, but slices and maps behave like references? Or not? I've read that large structs are better passed by pointer, ch